Two human trials of mRNA technology raised hopes of an effective HIV vaccine.
The virus that causes AIDS poses particular challenges for vaccine makers: It disguises itself from our immune system, and its various strains are so different that humans’ immune response usually only targets one variety.
But the new results suggest the possibility of vaccines that produce broad responses, and which could be delivered in a single injection.
There are still hurdles — many volunteers developed unpleasant skin reactions, and a full vaccine may be years away — but alongside the recent approval of lenacapavir, a drug that can prevent HIV infection with just two injections a year, the trials represent real progress in a decades-long battle against a once-unstoppable disease.